Climate change adaptation: determining what will grow where

Globally, agricultural systems face a struggle to feed a projected 9 billion people by 2050. Given the changes in climate and climate variability that are also projected to occur during this century, a comprehensive policy brief - launched at GCARD2 by the CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS) - has warned that a complete recalibration of where specific crops are grown and livestock are raised will be required.

In some places breeding and planting more resilient varieties may be an option, but in other areas adaptation will involve replacing maize, rice or wheat with crops such as cassava, banana, yam, cowpea or millet that are more likely to remain productive in a warming climate. "This recalibration of agriculture will eventually extend beyond what is grown and raised," says Philip Thornton, author of the report and a CCAFS theme leader. "The world's many cultures will need to adapt to the changing dinner menu forced upon them by climate change."

"Recalibrating agriculture in the face of climate change is more than planting crops that can tolerate warmer weather," Thornton adds. "Some commodities, for example, can grow in higher temperatures but cannot resist the insects and diseases whose prevalence will increase. Others can tolerate a lack of water but not the sporadic flooding that occurs with more frequent weather extremes."

Adaptation, therefore, will require an understanding of what is likely to happen to particular crops in specific parts of the world, in order to devise targeted approaches. Potato cultivation, for example, is best suited to cooler climates so rising temperatures are likely to reduce yields. Warmer winters may allow bananas to be grown instead in some places, but not if climate change also reduces rainfall.

Climate crossroads

Maize, rice and wheat are not the only agricultural products that are likely to suffer. The cost of feeding livestock with maize will become more expensive, and the availability of fish, which are particularly susceptible to higher temperatures and higher ocean salinity, will become increasingly constrained. In some areas, different plants, breeds and species can provide substitutes, but in others, more radical adaptation is the only option.

Higher temperatures and unpredictable rainfall will also alter underlying ecosystems that support agriculture. "Ecosystem changes due to climate change may spawn shifts in the intensity of pests and diseases that will further limit food production. Indeed, even if crops could withstand increased temperatures and decreased rainfall, their yields could drop because of these scourges," says Thornton. The policy brief suggests that integrated pest management and genetically modifying crops to develop or enhance resistance are two of the options that could help to control outbreaks.

The policy brief also warns that freshwater resources, already constrained in several regions, will become even less reliable. Understanding the impacts of climate change on water resources in different parts of the world and devising management strategies that conserve water are a critical focus of climate change adaptation. Producing 'more crop per drop' is already a priority, but the report states that further research is needed to explore alternative sources of water for agriculture, such as energy efficient systems that recycle wastewater or remove salt from ocean water.

Ensuring agriculture thrives

Despite the challenges, the report makes a series of recommendations to help ensure that agriculture not only survives but thrives. It recommends significantly raising the level of global investment in sustainable agriculture and food systems and implementing financing initiatives to help agricultural production systems become more resilient to weather variability and shocks, while contributing significantly to mitigating climate change.

The report also highlights the importance of reshaping food access and consumption patterns to ensure basic nutritional needs are met, developing specific programmes and policies to assist populations and sectors that are most vulnerable to climate changes and food insecurity, and establishing robust emergency food reserves as well as a financing capacity that delivers rapid humanitarian responses to vulnerable populations threatened by food crises. To help decision makers create the necessary socio-economic conditions (development of markets, infrastructure and political stability) to enable vulnerable populations to adapt to climate changes, CCAFS has been working with governments, civil society, academics and the private sector in Africa and South Asia to develop future scenarios that combine socio-economic and climate indicators.

"The good news is that if farmers and food producers start to adapt now, they can stave off some of the severe food production and distribution scenarios presented in this research. But they can't face these complex, interrelated problems, which vary from crop to crop and region to region, alone," Thornton adds. "They need support from the highest levels."

Dialogue and policy action

Significant steps towards addressing these needs were highlighted through GCARD2. Experts from major initiatives at international*, regional** and national*** levels presented their work and met together to discuss how to work together effectively to address climate change implications in agriculture. A special session devoted to environmental resilience in the context of climate change concluded that much benefit can be gained from greater commitment to existing partnerships, networks and actions, rather than establishing new structures. Participants called for greater use of, and support to, regional learning platforms to co-generate, share knowledge and inform policymakers with robust and understandable data so that locally-appropriate solutions can be put in place.

Great collective enthusiasm for effectively linking national and international initiatives, to enable capacity development, research and knowledge sharing across different regional contexts was demonstrated. Participants also emphasised the need to rapidly seek additional resources to ensure that these links and intentions turn into actions, with time-bound delivery, to meet the pressing climate change challenges we all now face.

* CCAFS, World Meteorological Organization, Global Research Alliance for Agricultural Greenhouse Gases, Inter-regional actions to combat desertification in the 'Great Green Wall'
** Climate change adaptation research networks in West Asia and North Africa and among agricultural universities in Africa
*** Uruguay, Mozambique and Ghana